Obtain tissue from human breast cancers from various clinical associates who have agreed to participate in the study and will furnish initial and follow-up records on each patient from whom tissue is obtained. Quantitatively analyze the EBP from human carcinomas representing the primary disease as well as those representing the metastatic disease. Determine the absolute concentration range of EBP per mg of cytoplasmic protein. Define biochemically the chromatin acceptor(s) for EBP in experimental animal mammary tumor systems.